CVE-2026-50577

HIGHPre-NVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 75% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

ePA 3.x Integration implements the authorization workflow and writes Medical Information Objects to Germany's electronic patient record. Prior to 1.3.0, ePA 3.x Integration leaves request_counter unchanged in app/vau/VAUProtokoll.py while constructing VAU messages. The frozen client request counter causes the server side to reuse AES-GCM nonce and key combinations across responses. A network attacker who collects repeated ciphertexts can recover the XOR of plaintexts and use predictable inner HTTP headers and JSON fields to recover sensitive data, including patient health records. Repeated nonces can also enable recovery of the GHASH authentication key through the Joux forbidden attack, allowing forged AES-GCM messages and injection of malicious responses. The response-counter check also fails to maintain last_response_counter, weakening replay and ordering validation. This issue is fixed in version 1.3.0.

CVSS v3
7.4
EG Score
7.4(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity74% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

August 18, 2026

Last Modified

September 8, 2026

Advisory Details (5)

Auto-updated Aug 18, 2026
Patch available. Sources: github_commit, github_pr, github_release, github.
generic

Eingefrorener Counter: Nonce-Wiederverwendung in fbeta ePA3-Service

https://www.machinespirits.de/advisory/df27cd
github Patch Available

AES-GCM Nonce Reuse via Frozen VAU Request Counter · Advisory · fbeta-GmbH/ePA3-Service-OpenSource · GitHub

https://github.com/fbeta-GmbH/ePA3-Service-OpenSource/security/advisories/GHSA-vmfm-3f7g-r9qg
github_release Patch Available

1.3.0

Patch available: fbeta-GmbH/ePA3-Service-OpenSource 1.3.0

https://github.com/fbeta-GmbH/ePA3-Service-OpenSource/releases/tag/1.3.0
github_pr Patch Available

fix: Add last response counter to VAUKanal for improved response vali…

Patch available: fbeta-GmbH/ePA3-Service-OpenSource 1.3.0 (PR #10 merged 2026-05-27)

https://github.com/fbeta-GmbH/ePA3-Service-OpenSource/pull/10
github_commit Patch Available

commit 85c4c516088c (fbeta-GmbH/ePA3-Service-OpenSource)

Patch available: fbeta-GmbH/ePA3-Service-OpenSource 1.3.0 (contains commit 85c4c516088c)

https://github.com/fbeta-GmbH/ePA3-Service-OpenSource/commit/85c4c516088c38b9cf2343f388ad67a6744e9814

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 50× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 21:51 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-17 21:49 UTCEG score recompute
  4. 2026-09-16 21:56 UTCEG score recompute
  5. 2026-09-16 14:08 UTCEPSS rescore
  6. 2026-09-16 10:08 UTCEG score recompute
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-15 09:49 UTCEG score recompute
  9. 2026-09-13 23:05 UTCEG score recompute
  10. 2026-09-13 16:47 UTCEPSS rescore
  11. 2026-09-12 23:57 UTCEG score recompute
  12. 2026-09-12 00:48 UTCEG score recompute
  13. 2026-09-11 14:53 UTCEPSS rescore
  14. 2026-09-11 13:14 UTCEG score recompute
  15. 2026-09-10 12:40 UTCEG score recompute
  16. 2026-09-10 09:35 UTCEPSS rescore
  17. 2026-09-09 08:51 UTCEG score recompute
  18. 2026-09-08 22:01 UTCEPSS rescore
  19. 2026-09-06 22:24 UTCEG score recompute
  20. 2026-09-06 13:47 UTCEPSS rescore
  21. 2026-09-05 23:16 UTCEG score recompute
  22. 2026-09-05 00:07 UTCEG score recompute
  23. 2026-09-04 12:08 UTCEG score recompute
  24. 2026-09-04 05:06 UTCEPSS rescore
  25. 2026-09-03 00:58 UTCEG score recompute
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  1. 2026-09-02 14:12 UTCEPSS rescore
  2. 2026-09-02 01:45 UTCEG score recompute
  3. 2026-09-01 13:54 UTCEPSS rescore
  4. 2026-09-01 13:31 UTCEG score recompute
  5. 2026-09-01 04:40 UTCEPSS rescore
  6. 2026-08-31 02:15 UTCEG score recompute
  7. 2026-08-30 19:17 UTCEPSS rescore
  8. 2026-08-30 03:01 UTCEG score recompute
  9. 2026-08-30 01:22 UTCEPSS rescore
  10. 2026-08-29 03:49 UTCEG score recompute
  11. 2026-08-28 21:41 UTCEPSS rescore
  12. 2026-08-27 20:35 UTCEG score recompute
  13. 2026-08-27 14:25 UTCEPSS rescore
  14. 2026-08-26 21:11 UTCEG score recompute
  15. 2026-08-26 14:46 UTCEPSS rescore
  16. 2026-08-25 22:00 UTCEG score recompute
  17. 2026-08-25 13:49 UTCEPSS rescore
  18. 2026-08-24 22:51 UTCEG score recompute
  19. 2026-08-24 11:17 UTCEG score recompute
  20. 2026-08-23 00:35 UTCEG score recompute
  21. 2026-08-23 00:19 UTCEPSS rescore
  22. 2026-08-22 01:27 UTCEG score recompute
  23. 2026-08-21 23:49 UTCEPSS rescore
  24. 2026-08-21 02:09 UTCEG score recompute
  25. 2026-08-20 22:55 UTCEPSS rescore
  26. 2026-08-20 03:00 UTCEG score recompute
  27. 2026-08-19 17:04 UTCEPSS rescore
  28. 2026-08-19 15:25 UTCEG score recompute
  29. 2026-08-19 14:58 UTCEG score recompute
  30. 2026-08-18 17:21 UTCEG score recompute
  31. 2026-08-18 17:07 UTCEG score recompute
  32. 2026-08-18 17:04 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-50577?
CVE-2026-50577 is a high vulnerability published on August 18, 2026. ePA 3.x Integration implements the authorization workflow and writes Medical Information Objects to Germany's electronic patient record. Prior to 1.3.0, ePA 3.x Integration leaves requestcounter unchanged in app/vau/VAUProtokoll.py while constructing VAU messages. The frozen client request counter…
When was CVE-2026-50577 disclosed?
CVE-2026-50577 was first published in the National Vulnerability Database on August 18, 2026, with the most recent update on September 8, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-50577 actively exploited?
CVE-2026-50577 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 75.5% of all scored CVEs.
What is the CVSS score of CVE-2026-50577?
CVE-2026-50577 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-50577?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-50577, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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